uros-db commented on code in PR #15834:
URL: https://github.com/apache/iceberg/pull/15834#discussion_r3014957872


##########
format/spec.md:
##########
@@ -242,10 +242,12 @@ For `geometry` type, the CRS does not affect geometric 
calculations, which are a
 
 The default CRS value `OGC:CRS84` means that the objects must be stored in 
longitude, latitude based on the WGS84 datum.
 
-Custom CRS values can be specified by a string of the format 
`type:identifier`, where `type` is one of the following values:
-
-* `srid`: [Spatial reference 
identifier](https://en.wikipedia.org/wiki/Spatial_reference_system#Identifier), 
`identifier` is the SRID itself.
-* `projjson`: 
[PROJJSON](https://proj.org/en/stable/specifications/projjson.html), 
`identifier` is the name of a table property where the projjson string is 
stored.
+Non-defaullt CRS values are specified by any string that uniquely identifies 
coordinate reference system associated with this type.
+To maximize interoperability suggested (but not limited to) formats for CRS 
are:
+* `authorithy:identifier` - where `authorithy` represents some well known 
authorities - examples are `OGC:CRS84`, `OGC:CRS83`, `OGC:CRS27`.
+* `inlined_projjson` - Inlining whole CRS definition in 
[PROJJSON](https://proj.org/en/stable/specifications/projjson.html) format.
+* `srid:identifier` - [SRID - Spatial reference 
identifier](https://en.wikipedia.org/wiki/Spatial_reference_system#Identifier), 
`identifier` is the SRID itself.
+* `projjson:table_property_name` - where `table_property_name` is the name of 
a table property where the projjson string is stored.

Review Comment:
   ```suggestion
   * `authorithy:identifier`- A reference using a well-known authority and its 
identifier. For example: `OGC:CRS83`.
   * `srid:identifier` - A reference using a Spatial Reference Identifier 
(SRID), where identifier is the numeric SRID value. For example: `SRID:0`.
   * `projjson` - A complete CRS definition embedded directly using the 
[PROJJSON](https://proj.org/en/stable/specifications/projjson.html) 
specification.
   * `projjson:table_property_name` - A reference to a CRS definition stored as 
a table property, where `table_property_name` identifies the property 
containing the 
[PROJJSON](https://proj.org/en/stable/specifications/projjson.html) string.
   ```



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to